pytest: fixtures offline_flake_hook init

pkgs/clan-cli/clan_lib/conftest.py

@@ -3,4 +3,5 @@ pytest_plugins = [
     "clan_cli.tests.hosts",
     "clan_cli.tests.sshd",
     "clan_cli.tests.runtime",
+    "clan_lib.fixtures.flake_hooks",
 ]

pkgs/clan-cli/clan_lib/fixtures/flake_hooks.py

@@ -0,0 +1,31 @@
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+from clan_lib.cmd import RunOpts, run
+from clan_lib.nix import nix_command
+
+
+def substitute_flake_inputs(clan_dir: Path, clan_core_path: Path) -> None:
+    flake_nix = clan_dir / "flake.nix"
+    assert flake_nix.exists()
+
+    content = flake_nix.read_text()
+    content = content.replace(
+        "https://git.clan.lol/clan/clan-core/archive/main.tar.gz",
+        f"path://{clan_core_path}",
+    )
+    flake_nix.write_text(content)
+
+    run(nix_command(["flake", "update"]), RunOpts(cwd=clan_dir))
+
+    flake_lock = clan_dir / "flake.lock"
+    assert flake_lock.exists(), "flake.lock should exist after flake update"
+
+
+@pytest.fixture
+def offline_flake_hook(clan_core: Path) -> Callable[[Path], None]:
+    def patch(clan_dir: Path) -> None:
+        substitute_flake_inputs(clan_dir, clan_core)
+
+    return patch